The thing about ethnic feuds like Rwanda is twofold, one practical, one emotional. The practical problem is that renouncing retailiation in a lawless area is physically dangerous(Romans does not make clear whether or not a clan chief is in the place of "Caesar" when there is no one else to do that job, by the way. The Bible does however approve of Abraham's rescue of Lot. So whatever). Which is one thing to remember when we judge such things; sometimes escapeing a "cycle of violence" is humanly impossible and the West only did so because state-sponsored warfare became efficient enough to suppress mere vendetta by rendering other factions incapable of fighting. The emotional problem is that when the issue is someone that you love, there is a feeling that forgiveness is not yours to give. These two problems are not logically incompatable with forgiveness. They are however, psychologically difficult to reconcile with forgiveness.